1. Field of the Invention
This invention relates to a system for the magnetic suspension of objects.
2. Description of the Prior Art
DE-42-10-741 (Fremerey) discloses a magnetic suspension system comprising an electromagnet and a first permanent magnet mounted to a fixed or movable support structure, an object provided with a second permanent magnet and arranged for suspension at a position below the electromagnet, by an attractive force developed between the two permanent magnets, detector means mounted in a fixed position to detect the magnetic field of the second permanent magnet, and control means for supplying an electrical current to the electromagnet when the magnetic field detected by the detector means changes from the field which is detected when the object is at the predetermined position, the electrical current being varied in accordance with an output signal of the detector means to maintain said object in a predetermined position relative to the electromagnet.
A disadvantage of the Fremerey system is that it uses a considerable amount of current to suspend the object at the predetermined position. Furthermore, the suspended object will be irrecoverably pulled into contact with the support structure by the attractive force between the permanent magnets, when the object moves too close to the support structure.